I'm a skinny guy too so I know what you are going through. I got up to 217 this spring before I started cutting down for summer. I'm down to 202 now :(

To get bigger, you have to eat EVERYTHING IN SIGHT. Seriously. Quality food gets more quality results, but eating more is the key thing here. You want as many calories as possible. I was mixing chocolate milk with my protein shakes and eating bread and pasta all day long.

Take two days in your week, write down everything you eat for each day, and then map out the protien/carb/fat for each food item and total them for each day. Try and get 1g of protein per .lbs of bodyweight. Avoid too much obviously shitty food, but if you just had a big day of legs then a big cheeseburger won't hurt.

Do big heavy compound movements as often as possible. Cut cardio down to practically nothing.

You could also try some of the natural Testosterone boosting supplements out there. I havent been happy with any of the research yet for pretty much ANYTHING marketed as a T-booster, but some people I know are happy with their results.

I've given up on ever being a small guy, or seeing the underside of 300lb. I have accepted this, the fact that I've gotten noticeably bigger, and stronger, makes me quite content. You don't need Jersey Shore muscles, you need to lift, and eat, until you look like me. Huge, in every possibly meaning of the term.

I do not aspire to be great, or even good, I hope to suck a little less then last class.

I was always happy with strength gains. It all comes down to what you hope to accomplish by training. It will be difficult for me to get bigger, but my bench went from 95% of my body weight at 20 years old to 160% at 35. If I build any mass, it is completely by accident LOL.